- Thread starter lydz
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Between mine and yours you are missing the D1 diode.
I will check with the headphone tomorrow. My Retroelektroik supergun has stopped outputting sound so I cannot even check if there is audio from the Jamma edge.
I will check with the headphone tomorrow. My Retroelektroik supergun has stopped outputting sound so I cannot even check if there is audio from the Jamma edge.
Should I remove the diode then?
I would think D4 and CC16 would need populated to complete the pot circuit but that's just assuming things. As of right now the pin appears to be floating coming out of the pot without CC16 populated although there could be a trace on the other side... The multi however seems heavily customized so I'd get input from the maker before throwing components on.
@ekorz your picture shows the Jamma edge unifier missing.
The RCA connector has no audio amplification. That's on the tiny edge connector.
There should be a 2-to-1 Jamma edge unifier that takes sound from the tiny edge into Jamma out.
You can see the sound routing here, appears to be on the 5th pin from the left. Pls. double check before blowing up the amp/speaker..
The RCA connector has no audio amplification. That's on the tiny edge connector.
There should be a 2-to-1 Jamma edge unifier that takes sound from the tiny edge into Jamma out.
You can see the sound routing here, appears to be on the 5th pin from the left. Pls. double check before blowing up the amp/speaker..
oh right. I took that unifier off so I could take photos of all the pcbs, but I do put it back on before booting it.@ekorz your picture shows the Jamma edge unifier missing.
The RCA connector has no audio amplification. That's on the tiny edge connector.
There should be a 2-to-1 Jamma edge unifier that takes sound from the tiny edge into Jamma out.
You can see the sound routing here, appears to be on the 5th pin from the left. Pls. double check before blowing up the amp/speaker..
RCA out gives me line level audio, but the pot should still raise/lower that, right?
I don't have this board but AFAIK the pots are generally used to regulate the amplified audio which goes through the JAMMA edge.
Line level outputs never have pots because you're supposed to use them with an amplifier which will provide you a volume control. There are some notable exceptions such as Taito F3 where you have the possibility of lowering or increasing the volume via software in the test menu and CPS-2 which (again, AFAIK) do the same thing, but via hardware buttons. This can also be proven by looking at Capcom's Q-Sound amplifier which doesn't have a pot, because you're supposed to use it with the board's own volume control.
Line level outputs never have pots because you're supposed to use them with an amplifier which will provide you a volume control. There are some notable exceptions such as Taito F3 where you have the possibility of lowering or increasing the volume via software in the test menu and CPS-2 which (again, AFAIK) do the same thing, but via hardware buttons. This can also be proven by looking at Capcom's Q-Sound amplifier which doesn't have a pot, because you're supposed to use it with the board's own volume control.
Line level is a single, fixed level of 'volume' decided on by vendors.
https://en.wikipedia.org/wiki/Line_level
So yeah, it's impossible to adjust that with the pot. The pot adjusts the amplification of the jamma mono output only. Line-level audio should be amplified by a suitable external amplifier. Connect a speaker to the Jamma edge, there should be mono sound, and the pot should adjust it.
You can get the Q-Sound spatial audio by the RCA plugs.
Also you can use a normal amplifier with the RCA plugs to enjoy the spatial effect. Capcom's Q-Sound amp pcb is just a normal stereo amp, it contains no sound processing tech. Q-Sound relies on the time delay between both ears to do special tricks and spatializing
@suverman Edited my post too.
https://en.wikipedia.org/wiki/Line_level
So yeah, it's impossible to adjust that with the pot. The pot adjusts the amplification of the jamma mono output only. Line-level audio should be amplified by a suitable external amplifier. Connect a speaker to the Jamma edge, there should be mono sound, and the pot should adjust it.
You can get the Q-Sound spatial audio by the RCA plugs.
Also you can use a normal amplifier with the RCA plugs to enjoy the spatial effect. Capcom's Q-Sound amp pcb is just a normal stereo amp, it contains no sound processing tech. Q-Sound relies on the time delay between both ears to do special tricks and spatializing
@suverman Edited my post too.
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I think those 2 examples came to mind for me. They are 2 systems I use on jamma that have at least some way to raise/lower volume from the line level RCA ports. I thought maybe the test mode would have an option. Maybe something is underpowered and it’s at max already...
either way, my potentiometer doesn’t adjust volume off the jamma edge either! Time for the probe...
Ehh
If the 12V stage is taped off, the amplifier on the qsound board will never amplify the sound for the jamma edge so there you go. (so what you posted earlier makes sense now). I've no idea why they tape off the 12V, maybe for testing and @lydz can explain better. I didn't know it was taped off. @suverman can you explain/show where _exactly_ there is tape so i can understand better?
https://drive.google.com/open?id=11Qu9W53UCVIiL_ULNXj9vIbQCyjoZQFH
If you look closely you can see the 12V on the Jamma edge of CPS A board insulated. Also My CPSA board has the normal CPS A board audio components maybe that's why they insulated it?
That seems wrong.
I can understand that the main board amp is powered off, it might cause unintended buzzing or feedback.
But if your Qsound board has no 12V power input as a result, it will never output mono amplified sound into the Jamma edge.
Did you meter the 12V area on the qsound board? Does it get +12V DC with the tape in place?
Edit: Technically you can do this as follows, but i'm at work, have no 1.5CPS with me, or at home, and no easy access.
- Remove the tape from the jamma unifier edge.
- Add the tape to the jamma edge on the CPS1 A board
- Put the jamma unifier back on. DONT POWER OR CONNECT TO POWER yet.
- Grab a multimeter and check if the qsound board now has +12V continuity (set to ohms, meter should go to 0 ohms or super low ohms)
- Check if there is +12V on the solder tabs behind the CPS1 A board (maybe there is +12V in the board interconnectors? And a path back which we don't need.)
There should be no path from the front jamma unifier +12V input to the main CPS1 a board 12V.
If there is no path, you can move the tape from the unifier to the CPS1 a board and solve this problem.
If there is a path back, i'm not sure how to proceed without cutting up some power path somewhere. The tape must be added for some reason.
Could be an issue with 'normal' cps1 A boards, they probably used those because a shortage of dash/1.5 mobo without the amp section populated..
I can understand that the main board amp is powered off, it might cause unintended buzzing or feedback.
But if your Qsound board has no 12V power input as a result, it will never output mono amplified sound into the Jamma edge.
Did you meter the 12V area on the qsound board? Does it get +12V DC with the tape in place?
Edit: Technically you can do this as follows, but i'm at work, have no 1.5CPS with me, or at home, and no easy access.
- Remove the tape from the jamma unifier edge.
- Add the tape to the jamma edge on the CPS1 A board
- Put the jamma unifier back on. DONT POWER OR CONNECT TO POWER yet.
- Grab a multimeter and check if the qsound board now has +12V continuity (set to ohms, meter should go to 0 ohms or super low ohms)
- Check if there is +12V on the solder tabs behind the CPS1 A board (maybe there is +12V in the board interconnectors? And a path back which we don't need.)
There should be no path from the front jamma unifier +12V input to the main CPS1 a board 12V.
If there is no path, you can move the tape from the unifier to the CPS1 a board and solve this problem.
If there is a path back, i'm not sure how to proceed without cutting up some power path somewhere. The tape must be added for some reason.
Could be an issue with 'normal' cps1 A boards, they probably used those because a shortage of dash/1.5 mobo without the amp section populated..
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